<html>
    <head>
        <title>Test</title>
        <style>

body { margin:0; }
div {min-width:min-content;}
frameset {min-height:min-content;}

splitter { border:none; }
splitter:hover { background:red; }

section { background:gold; }

        </style>
    </head>
    <body>

      <frameset rows="64px,*">
        <frameset cols="64px,*">
           <div>Framesets can</div>
           <splitter/>
           <div>host</div>
        </frameset> 
        <splitter/>
        <frameset cols="2*,1*">
           <div>any arbitrary DOM element</div>
           <splitter/>
           <section>as a split panels</section>
        </frameset> 
      </frameset>

    </body>
</html>